Gender disappointment?

Found out yesterday I'm expecting a gorgeous little baby girl and I'm over the moon of course, as I would have been with a boy. However my boyfriend had his heart set on a little boy and I totally understand it because most boys want sons. He hasn't expressed he's disappointed but I can tell he's feeling kind of low about it. I don't think he's doing it on purpose and i know he will love our daughter endlessly when she arrives as he does now. But is there anything I can do to make him more excited for a little girl? 💗